The viscera are physiologically related, and pathologically affected. Problems in one viscus may affect the others. This is called transmission of disease. According to the Five Elements theory, disease transmission among the five Zang viscera has two categories, and follows the inter-promotion (mother involved with child) and inter-restriction (abnormal as over restrained or reversed) relationships.
(1)Transmission of disease with the inter-promotion relationship
(a)Abnormal change of the mother affects the child. The disease is transmitted from mother viscera to child viscera. For example, normally, the mother Liver (Wood) promotes the child Heart (Fire). The pathogenic situation of “Wood failing to nourish Fire” syndromes arises with the deficiency of both Liver Yang and Heart Yang.
(b)Disorder of the child affects the mother. The disease progression from the child viscus to the mother viscus. For example, normally, the mother Kidney (Water) promotes the child Liver (Wood). But the deficiency of Liver Yin affects the Kidney and causes deficiency of Kidney Yin. The same syndrome of “raging Fire of the Heart” transmitting to the Liver occurs, because the raging Heart Fire gives rise to Liver Fire.
(2)Transmission of disease with the inter-restriction relationship
There are two cases: over restraint and reverse restraint. The treatment principle is to change the visceral imbalance and to restore visceral harmony function by inhibiting the strong viscera and supporting the weak one.
(a)Over restraint is a diseased condition. For example, the Liver (Wood) in excess encroaches on the Spleen (Earth) because hyperactive Liver Qi invades the Spleen and stomach.
(b)Reversed restriction is a diseased condition. For example, raging Liver Fire affects the Lung’s dispersing and descending, or “Fire of the Liver (Wood) makes the Lung (Metal) suffer.” The clinical syndromes are over-Fired in both the Liver and the Lung. An effective treatment is to release Liver Fire stasis. Therefore, reinforcing the Spleen should improve the chronic consumption of the Lungs, described as “reinforcing Earth to strengthen Metal.”
A particularly useful treatment principle in acupuncture is to “Reinforce the ‘mother’ in deficiency conditions, and to reduce the ‘child’ in excess conditions.” In acupuncture treatment, the mother meridian points are usually reinforced if the child meridians are deficient. For example, for the Lung deficiency, patients’ Taibai (SP 3), the Shu (Earth) point of the Spleen meridian, is often used to reinforce. If, however, the syndrome is in excess, the child Kidney meridian points are usually reduced. For example, because Yingu (KI 10) is the He (Water) point of the Kidney meridian, reducing manipulation at Yingu (KI 10) often reduces the exuberant Lung Fire. In both examples, the points of the Lung meridian can also be selected, i.e. Taiyuan (Lu 9), the Lung’s Shu (Earth) point for reinforcement, and Chize (Lu 5) the Lung’s He (Water) point for reduction.
Chinese medical diagnosis is based on the belief that “all internal illness can be manifested externally.” With this understanding, TCM physicians are trained to discern subtle symptoms or manifestations to investigate pathology. when a viscus is diseased, some corresponding parts or organs under the body surface will appear abnormal in color, voice, flavor, finger, pulse, and so on. It gives a very direct hint of diagnosis. The combined interrelationship of the five elements with syndrome differentiation helps to make complete diagnoses.
The Five Elements theory is appropriate for the activities of the body within its environment. The interrelationship of the Five Elements sequences is basic in TCM development, but supplementary theories have been developed to explain some physiological and pathological changes. For instance, the descending actions of the Lungs (sending down essence and Qi to control the passage of Water) help the Kidneys, but the Kidneys also help the Lungs to inhale because the Kidneys dominate the reception of air. Insufficient Kidney function may lead to dyspnea, characterized by shortened inhalation and prolonged exhalation.
Water and Fire are two of the five elements, but they are also used as pathogens in etiology and as syndrome names in diagnosis. Fire has different meanings in different places. Physiologically, Fire is the heat or vital energy necessary for all life activities, particularly the Spleen’s function in digestion, absorption, and assimilation. Vital Fire is equivalent to Kidney Yang produced by the Kidneys.
Fire (Heart) promotes Earth (Spleen) through blood and energy circulation. Therefore, when “Fire fails to promote Earth” in chronic diarrhea accompanied by edema and cold intolerance, treatment is to “reinforce Fire to promote Earth.” Other times, however, Fire means the Heart. “Coordination of Water and Fire” is the physiological interrelationship between the Kidneys and the Heart. If Kidney Yin (Water) is insufficient to check the activity of the Heart (Fire), there may occur “discord of Water and Fire,” marked by restlessness and insomnia.
The validity of the Five Elements theory has been proven by thousands of years of clinical practice and research. However, the point is not just the number, but the mutual regulatory relationship between different types of matter to be recognized. This theory explored human intangible energy systems thousands of years ago and discovered the interpromoting (producing) and interacting (restricting) relationships among different systems. In the TCM philosophy, Qi is the most basic substance which composes the whole universe. Qi is composed of Yin and Yang. The interaction of Yin and Yang produces the Five Elements, but every element still includes Yin and Yang. Yin–Yang theory is the law of contradiction; whereas the Five Elements doctrine is the system theory of TCM. Yin–Yang theory and the Five Elements theory support each other.
Although based on a different philosophy, Western medicine’s feedback control theory explains physiological phenomena and pathological change somewhat similarly, though it limits the theory to a feedback mechanism. But in accepting basic rules of self-balance, modern physiology no longer limits feedback control to research on neurohumoral regulation; it also applies feedback control research to immunology, molecular biology, genetic information, gene regulation, and detailed specific microcosms. However, Western medicine might never approach a holistic view of the body as an intangible system as well as the Five Elements theory does.